The invention concerns spacecraft power systems and in particular is directed to a spacecraft battery thermal management system for controlling the temperature of batteries within a spacecraft.
Spacecraft batteries must be maintained within specified temperature ranges during operation of the spacecraft. Excess heat generated by the batteries is dissipated using radiator panels thermally coupled to the batteries. The radiator panels are conductively bonded to one or more battery cells and are arranged with at least one face of the panel exposed to the cold temperatures of space. During charging operations, heat is supplied to the spacecraft batteries using power consuming heaters. The thermal management systems used in conventional spacecraft, however, constrain the overall payload capabilities of the spacecraft.
Spacecraft operating in geosynchronous orbits use North and South facing surfaces for transponder panels containing payload and bus equipment configured for the spacecraft mission. To minimize solar impingement and diurnal variation, spacecraft batteries typically are arranged with the conductively bonded radiators also facing North or South. One such arrangement is represented in the block diagram depicted in FIG. 1. North battery 1 and South battery 2 are shown in FIG. 1 conductively bonded to thermal radiator 3 and thermal radiator 4, respectively. When arranged in a spacecraft operating in a geosynchronous orbit, North battery 1 and thermal radiator 3 are positioned with a face 3a of thermal radiator 3 exposed to space on a North facing side of the spacecraft (not shown) and South battery 2 and thermal radiator 4 are positioned with a face 4a exposed to space on a South facing side of the spacecraft.
Spacecraft batteries typically require lower temperatures than those required by other payload and bus equipment in the spacecraft. Accordingly, the thermal radiating surface area required for the spacecraft batteries is greater than that required for the other payload and bus equipment. When positioned on the North or South facing sides of the spacecraft, the spacecraft batteries and their conductively bonded thermal radiators significantly reduce the area available to other payload and bus equipment on the North and South facing sides of the spacecraft. A need exists for improved spacecraft battery thermal management systems that increase the amount of space available for mission critical payload and bus equipment while maintaining the temperature ranges required by the spacecraft batteries.